Primary Hyperparathyroidism in MEN2 Syndromes.

One of the components of the classical form of MEN2 syndromes is primary hyperparathyroidism (PHP). It occurs in 20-30% of the typical MEN2A syndrome. Recently, the prevalence in ret gene carriers is rarer possibly due to the increased recognition of cases who have familial MTC only. PHP is diagnosed more frequently in association with the exon 11, 634 mutation of the ret gene-so there is phenotype/genotype correlation. The clinical manifestations of PHP in MEN2 are usually mild and the peak age of diagnosis is after the third decade. The treatment is surgical excision of the enlarged gland(s). Although there can be multigland disease in the parathyroids, it is frequently the case that both hyperplasia and adenoma may coexist, or even a single adenoma may be found during the investigation and finally during the operation. Patients with MEN2 syndromes should be screened for PHP with serum calcium measurements. The intensity of the screening should be higher in those carrying the ret mutations most frequently associated with this manifestation.